1. Field of the Invention
This invention relates to a heat-radiation structure of an electronic-unit box in which the heat-radiation property of the electronic-unit box mounted on a vehicle or the like is improved.
2. Background
FIGS. 7 and 8 show a conventional electronic-unit box.
An electronic-unit box 41 is integrally formed with synthetic resin, such that a rectangular hollowed inner peripheral wall 44 is formed so as to project in the inside of a box body 42 so that an air layer 45 for insulation and heat radiation is formed between the inner peripheral wall 44 and an outer peripheral wall 43. An electronic unit 47 is mounted in an inside space 46 of the inner peripheral wall 44. The electronic-unit box 41 is mounted on a vehicle and the electronic-unit box 41 is closed with a cover 48. The electronic unit 47 is used, for example, for fuel injection control, or the like.
In the foregoing conventional structure, however, when the electronic-unit box 41 is mounted in an engine room or the like, the temperature of the air layer 45 may become saturated so that cooling of the electronic unit 47 becomes insufficient.